The present invention relates to a novel method for preparing an organomonochlorosilane which serves as an intermediate material for the preparation of silylating agents or other various kinds of organosilicon compounds.
As methods for preparing organomonochlorosilanes represented by the formula: R.sup.1 R.sup.2 R.sup.3 SiCl starting from organodisiloxanes, there have conventionally been known, for instance, a method disclosed in Japanese Patent Provisional Publication No. 52-65226 in which an organodisiloxane is reacted with a dialkyldichlorosilane in the presence of hexamethylphosphoric acid triamide as a catalyst.
This method which makes use of dialkyldichlorosilanes accompanies formation of polysiloxanes as by-products. The polysiloxane is quite viscous and accordingly, when isolating, by distillation, the organomonochlorosilane as the subject product from the reaction solution, it is needed to extremely raise the temperature of the reaction vessel for distillation. Moreover, a viscous oily product remains in the reaction vessel after the distillation. This makes the post-treatment of the reaction vessel quite difficult. In addition, hexamethylphosphoric acid triamide used as the catalyst is one of carcinogens and, therefore, handling of the starting materials and treatment of waste liquor must be carefully carried out.